diff options
Diffstat (limited to 'drivers/gpu/drm/drm_gem.c')
| -rw-r--r-- | drivers/gpu/drm/drm_gem.c | 48 |
1 files changed, 33 insertions, 15 deletions
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index 4bf0a76bb35e..ac0524595bd6 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -223,23 +223,34 @@ static void drm_gem_object_handle_get(struct drm_gem_object *obj) } /** - * drm_gem_object_handle_get_unlocked - acquire reference on user-space handles + * drm_gem_object_handle_get_if_exists_unlocked - acquire reference on user-space handle, if any * @obj: GEM object * - * Acquires a reference on the GEM buffer object's handle. Required - * to keep the GEM object alive. Call drm_gem_object_handle_put_unlocked() - * to release the reference. + * Acquires a reference on the GEM buffer object's handle. Required to keep + * the GEM object alive. Call drm_gem_object_handle_put_if_exists_unlocked() + * to release the reference. Does nothing if the buffer object has no handle. + * + * Returns: + * True if a handle exists, or false otherwise */ -void drm_gem_object_handle_get_unlocked(struct drm_gem_object *obj) +bool drm_gem_object_handle_get_if_exists_unlocked(struct drm_gem_object *obj) { struct drm_device *dev = obj->dev; guard(mutex)(&dev->object_name_lock); - drm_WARN_ON(dev, !obj->handle_count); /* first ref taken in create-tail helper */ + /* + * First ref taken during GEM object creation, if any. Some + * drivers set up internal framebuffers with GEM objects that + * do not have a GEM handle. Hence, this counter can be zero. + */ + if (!obj->handle_count) + return false; + drm_gem_object_handle_get(obj); + + return true; } -EXPORT_SYMBOL(drm_gem_object_handle_get_unlocked); /** * drm_gem_object_handle_free - release resources bound to userspace handles @@ -272,7 +283,7 @@ static void drm_gem_object_exported_dma_buf_free(struct drm_gem_object *obj) } /** - * drm_gem_object_handle_put_unlocked - releases reference on user-space handles + * drm_gem_object_handle_put_unlocked - releases reference on user-space handle * @obj: GEM object * * Releases a reference on the GEM buffer object's handle. Possibly releases @@ -283,14 +294,14 @@ void drm_gem_object_handle_put_unlocked(struct drm_gem_object *obj) struct drm_device *dev = obj->dev; bool final = false; - if (WARN_ON(READ_ONCE(obj->handle_count) == 0)) + if (drm_WARN_ON(dev, READ_ONCE(obj->handle_count) == 0)) return; /* - * Must bump handle count first as this may be the last - * ref, in which case the object would disappear before we - * checked for a name - */ + * Must bump handle count first as this may be the last + * ref, in which case the object would disappear before + * we checked for a name. + */ mutex_lock(&dev->object_name_lock); if (--obj->handle_count == 0) { @@ -303,7 +314,6 @@ void drm_gem_object_handle_put_unlocked(struct drm_gem_object *obj) if (final) drm_gem_object_put(obj); } -EXPORT_SYMBOL(drm_gem_object_handle_put_unlocked); /* * Called at device or object close to release the file's @@ -315,6 +325,9 @@ drm_gem_object_release_handle(int id, void *ptr, void *data) struct drm_file *file_priv = data; struct drm_gem_object *obj = ptr; + if (drm_WARN_ON(obj->dev, !data)) + return 0; + if (obj->funcs->close) obj->funcs->close(obj, file_priv); @@ -435,7 +448,7 @@ drm_gem_handle_create_tail(struct drm_file *file_priv, idr_preload(GFP_KERNEL); spin_lock(&file_priv->table_lock); - ret = idr_alloc(&file_priv->object_idr, obj, 1, 0, GFP_NOWAIT); + ret = idr_alloc(&file_priv->object_idr, NULL, 1, 0, GFP_NOWAIT); spin_unlock(&file_priv->table_lock); idr_preload_end(); @@ -456,6 +469,11 @@ drm_gem_handle_create_tail(struct drm_file *file_priv, goto err_revoke; } + /* mirrors drm_gem_handle_delete to avoid races */ + spin_lock(&file_priv->table_lock); + obj = idr_replace(&file_priv->object_idr, obj, handle); + WARN_ON(obj != NULL); + spin_unlock(&file_priv->table_lock); *handlep = handle; return 0; |